Thanks for the suggestion.... seems perfect, except I can't get results from it. It grinds away at 1.25GB memory usage for a while then savest he GIF.
The GIF does contain the correct number of frames, bu they're all black
The brightness ranges of the images should be fine, as when I open them up in CCDSoft they're showing ok. But I wonder if the GIF conversion uses the full brightness range, hence my faint image (max of 1,600ADU out of 65,000ish) isn't showing anything when converted.
I'll keep plugging away at it on another night, when I have ADSL2 back, on dialup right now so not bothering to track down the help manual for ImageMagick.
Roger.